Technical Field
The present disclosure generally relates to an optical fiber-based safety system integrated into a power-over-fiber system. More particularly, but not exclusively, the present disclosure relates to a power-over-fiber (PoF) system having a high-flux electromagnetic energy transmitter coupled via a fiber-based conduit and a fiber-based safety system to an electromagnetic energy receiver that converts received light into electricity.
Description of the Related Art
Some aspects of technologies and related art that may be useful in understanding the present invention are described in U.S. patent application Ser. No. 14/124,993, which is now U.S. Pat. No. 9,800,091 issued to Nugent et al. The Nugent patent describes an aerial platform that receives power in the form of light (e.g., laser light) transmitted via an optical fiber from a remote optical power source. The platform comprises a receiver, which converts at least a portion of the received light to a different form of power, for example electric power. In the Nugent publication, the platform comprising the receiver also comprises a propulsion element, which consumes the different form of power to generate propulsive thrust. Supplying power to the aerial platform from a remote source enables the platform to remain aloft longer than a battery or fuel tank carried by the platform would allow. Transmitting the power in the form of light is preferable in many cases to transmitting electric power, because electrical conductors are generally heavier than optical fibers, and are hazardous in the presence of lightning or a high-voltage power line. The Nugent patent is incorporated herein by reference.
Another patent application that may be useful to help understand the present invention is U.S. patent application Ser. No. 14/263,858, which is also U.S. Patent Publication No. 2014/0318620 A1 to Kare et al. The Kare application describes a device for converting electromagnetic radiation into electricity along with other related systems and methods. In the application, electromagnetic radiation is converted into electricity via an expander (e.g., an optical “spike”) that includes a conical shape. The expander has an axis and a curved surface that is configured to reflect electromagnetic radiation away from the axis. The beam of electromagnetic radiation is expanded, and one or more energy conversion components receives the expanded electromagnetic radiation and generate electricity. With the expander's curved surface, a beam of electromagnetic radiation that has a large radiation flux is converted into a beam that has a larger cross-sectional area.
Some other aspects of technologies and related art that may be useful in understanding the present invention are described in U.S. patent application Ser. No. 11/776,527, which is now U.S. Pat. No. 7,813,646 B2 to Furey, and which describes a power over optical fiber system.
In the Furey patent document, a system provides power to remote equipment. In the system, a transmit unit having lasers transmits laser light over optical fiber to a receive unit having photovoltaic receivers. The photovoltaic receivers convert the laser light to electrical energy for the remote equipment. The receive unit also sends a feedback signal to the transmit unit, which the transmit unit uses to determine whether the lasers should be enabled for full power. The feedback signal sent by Furey's receive unit may be an electronic signal sent over a wire or a generated light-based signal sent over an optical fiber.
All of the subject matter discussed in the Background section is not necessarily prior art and should not be assumed to be prior art merely as a result of its discussion in the Background section. Along these lines, any recognition of problems in the prior art discussed in the Background section or associated with such subject matter should not be treated as prior art unless expressly stated to be prior art. Instead, the discussion of any subject matter in the Background section should be treated as part of the inventor's approach to the particular problem, which in and of itself may also be inventive.